Furnace wall and lining construction



' Jan. 12 ,'1926.

N. E. MACCALLUM FURNACE WALL AND LINING CONSTRUCTION Filed August 13 1924 f w enior: Mrrrwnljwoc a Patented 1.... 12, 1926.

Norman E. mAccALLuM, orrnonn xvinnn, 'rnimsnvazun.

FURNACE -WAI4IIAND LINING CONSTRUCTION.

Application filed August 13, 1924. serial' ]t'o. 731,720.

To all whom it may concern:

Be it known that I, NORMAN MAC- GALLUM, a citizen of the United States, and a resident of Phoenixville, county of Chester, State of Pennsylvania, have. invented certain new and useful Improvements in Furnace Wall and Lining Construction, of which the following is aspecification, reference being had to the accompanying 1 drawing.

It has been theex erience of metallurgists from the remotest timesin the smelting and heat treatments of iron and other metals and their ores that the walls and linings of furnaces when exposed to high and variable temperatures, even though the'limngs be composed of the most refractory materials, are subject to rapid disintegration requiring frequent repairs if not entire new units to replace those rendered totally useless. Such repairs and replacements add materially to the cost of operating a furnace installation and, therefore, to the'cost of the product of a furnace whatever be the nature of its output.

Another serious difliculty. with refractories is their expansion, contraction and other deformations due to the alternate heating and cooling of the furnaces brought about periodically by the shut-down for repairs, whether extensive or the contrary. It may be pointed out in illustration that, where exterior plates are used in ordinary furnace construction, particularly so in the case of open hearth furnaces, the refractory material built against the interior face of.

a plate gradually shrinks away'from the plate leaving av space which isa source of to danger, since, if moulten steel finds its way into the space, it is likely to cut its way on through the plate, thereby causing an expensive loss. t

In further explanation it may be stated that refractory linings, as ordinarily. constructed and used, becomeattached to the hearth, and that the shrinkage due to cooling causes contraction in thehearth which pulls the attached rotecting refractory material away from t e exterior plate, leaving an opening which does not close when the furnace is reheated.

It is the object of my invention to over come these disadvantages, to preserve the walls and hearth as far as possible, and to protect the exterior plates by means of a metallic strip construction which maintains the contact between the basic wall lining and the exterior plates.

A further advantage of my construction 66 consists in the fact that when" the basic lining is kept in contact with the exterior plates,water cooling is made easy and effective. Speaking further in this respect, it maybe said that, incertain furnaces such as electric furnaces, an adaptation of my invention would be far more effective than bricks, or the tubular metal containers WhlCh I have employed as described in U. S. Letters Patent No. 1,106,725, dated August 11, 1914, for the reasons just mentioned and as will be seen hereinafter.

There are still further advantages which accrue with the use of. my improved construction. These consist in 1 considerable economies of time, labor and materials as compared with the requirements for the ordinary construction" or for tubular containers. No mortar is necessary with my improved construction and it is evident that much labor willbe saved as "the use of the metal strips obviates handling a multiplicity of bricks or filling and placing a large number of tubes. It is advisable, however,

to use a binder of pitch or tar for the 86 basic material, which may be of an inferior type, such as dolomite instead of the more expensive magnesite. Moreover, as will be seen hereinafter, the lining material may be rammed into place after the steel construction is assembled.

In the accompanying drawing I have illustrated one embodiment of my invention in which Fig. 1 is a transverse cross section of a furnace showing details of my furnace-wall and lining construction. Fig. 2is a fragmentary view in" lan of the metallic ortionof the base 0 the hearth, showing" ow the construction may be applied. Fig. 3 is a fragmentary horizontal cross section on the line 3-3 of Fig. 1.

A rectangular base plate 1 rests in a horizontal position upon supports 2 which, in the illustration, are shown as I beams but may be of any type such as channel lates; These supports in turn restnpon ndamental supports, which are also shown as I beams 3, in a longitudinal position. These latter beams finally rest upon a suitable foundation which is not shown. The roof 4 may be composed of silica brick as usual. \The furnace walls '5 are provided with exterior binding plates 6 formed of steel or, any other suitable material. To' the base .plate 1 and the exterior binding plates 6 are secured a plurality of metal strips 7 preferably disposed inwardly and upwardly in the -mannershown. These metal strips are preferably made with flanges 8 through which rivets 9 may be passed to secure the strips 7 to the binding plates 6 and the base plate 1 in thedesired positi OIl- I 1 I After the metal strips 7 are attached to i the base plate 1 and the exterior binding E-liites 6, the spaces between the strips are ed with basic or neutral material, or a combination of such materials, as desired and as indicated at 10. When attaching'the metal strips 7 to the exterior binding plates 6 by means of rivets as shown, it will be found expeditious to begin at the top and attach them in a downward succession. It may also be pointed .out that the basic, neutral or combined material should be rammed compactly into place so as to reduce as much as possible the'porosity and surfaces exbe calcined before bein posed to thermal and chemical actions and to force the material against. the metallic .lustrations.

Cooling water may be circulated. in troughs 12, thepurpose being to cause the water to absorb heat from the exterior binding plates 6 which in turn abstract heat from" the basic material 10 in contact "with the binding plates. This cooling system should extend to the vicinity of the junction between the silica brick roof 4 and the basic materials of the side walls so that the cool ing effect will tend to reduce the harmful action between the basic wall and acid roof.'-

Any other system of cooling may be applied, but the construction shown.- is verysimple and very efl'ective since the basic material is packed againstthe exterior bind ing plate, t ereby causing the cooling-efi'ect to penetrate into the body of the refractory material. 7 g

As mentioned hereinbefore, as in the case of ordinary furnace-wall lining construction linings of refractory material are apt to be .pulled away from exterior binding plates,

leaving spaces which are sources of serious danger. With my construction as herein describedandillustrated, it is evident that the refractory material cannot-be pulled away 'from binding plates and that any shrinkage will occur in the hearth where it is softened by the intense heat.

My improved furnace-wall andlining as herembefore described is notlimited to any particular type of furnace and may be used in open hearth, electric, copper or any other furnaces" The exterior binding plates 6 may be of any size or shape desired. They should {be sufliciently strong to carr for holding in place the re ractory materials for the lining of the furnace walls and base of the hearth. While the exterior bind- "ing plates 6 and metal strips 7 may be composed of steel, any other suitable materials the strips 7 maybe employed for eitherloi both. It is apparent t at my invention may be. in? stalled in various forms .to meet particular requirements without departing from the spiritof the invention or the scope of the appended claims.

Having thus described my invention, I claim and desire to protect by Letters Patent of-the United States:

1. A'furnace comprising walls, exterior binding plates for .sald walls, a plurality of metal strips secured to and projecting inwardly ,and upwardly from said binding plates and a refractory material packed between said strips and rammed against said binding plates to prevent separation of the refractory material from said plates incident to shrinkage due to cooling of the furnace.

2. A furnace comprising a hearth, an exterior base plate for said hearth, a plurality of metal strips secured to and projecting in-- wardly and upwardly from said base plate,

and "a refractory material packed between said strips and said base binding plate into intimate binding contact with said plate.

3. A furnace wall comprising an exterior plate, meta-l strips attached to and extending inwardly and upwardly from .said'plates and a refractory material packed between said strips and said plate in intimate con- ,tact with said plate and strips.

4. .A-furnace comprising walls provided with exterior binding 'lates, a .hearth provided with a base binding plate, a plurarity, of metal strips secured to and projecting inwardly and upwardly from said binding plates and arefractory material packed between said strips and said binding plates in wit intimate contact therewith to'prevent acci dental s acing of the refractory material from sai d plates. a

5. A furnace wall comprising exterior binding plates, a plurality of spaced metal stri s having their inner edges provided portions to said plates, said strips extending flanges and secured at their flangedinwardly and upwardly from said bindingplates, and a refractory material held to- 1 gether between said strips. and said binding plates. r

In witness whereof, I have hereunto set my hand this 16th day of-August, 1924.

NORMAN E. MAOCALLUM. 

